Friction-board for drop-forging hammers.



J. A. BURGER. FRICTION BOARD FOR DROP FORGING-HAMMERS. APPLIGATION FILED AUG.14, 1907.

9013779. I Patented0ct.20,1 908.

JOHN A. BURGER, OF DETROIT, MICHIGAN.

I Specification of Letters Patent.

FRICTION-BOARD FOR DROP-FORING HAMMERS.

, Patented Oct. 20, 1908.

Application filed August 14, 1907. Serial No. 388,440.

.To all whom it may concern;

1 3e it known that I, JOHN A. BURGER, a c1t1 zen of the United States, residing at Detro1t,-in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in lirictioir-Boards for -1)rop-I*orging Hammers, of which the following is a specification.

As commonl constructed, the upper die and head of a rep-forging han'n'neris lifted by means of a wooden strip or board secured at one end to the head and passed between friction rolls which engage it with suflicient force to prevent its slipping when the rolls are turned to feed the board through and lift the great weight of the head. This heavy intermittent crushing action of the rolls often splits the board, making it dangcrtms to use, and soon by compressing the fibers, causes the board to loose its elasticity ,and consequent frictional quality which is essential to prevent slip'ping'and premature dropping of the head when raisedf This invention relates to an improved friction boardfor this purpose, and its object is to provide a board which is less liable to split, crack or break, has greater elasticity and strength, and will last much longer in use than the ordinary wooden strip or board commonly used. i

It is also an object of the invention to so construct the boardthat, should it split, the pieces would still be held in place and injury to the operator therefrom would be prevented. I

To this end the invention consists in forming a board of two or more thin strips which are secured together with a strengthening strip of suitable ma terial between, all as hereinafter more fully described, reference being bad to the accompanying drawing, in which,

Figure 1 is a diagrammatic front elevation of a drop-forging hammer, with a friction board embodying the invention, in place therein; Fig. 2 is a side elevation of the same with parts broken away toshow the friction rolls and board; l ig. 3 is a perspective detail of a portion of-a board embodying the inrention, and Fig. 4 is a similar view show ing a modified constrijiction.

As shown in the drawings, 1 is the machine bed having a seat for the lower die and 3 is a suitable upright frame having guides for the weighted head 4 whlch carries the upper die To this head one or more frlction boards 6 are secured at their lower ends,

these boards extending upward between suitable friction rolls 7 which are driven in any suitable manner, as by pulleys S on oneroll shaft same when the head has been raised to a predeteri-mned he ght to permit. it. to fall treely. One board 6 may be used m place of the two shown, but A prefer to use two as the narrower boards are less expensive to manut'acture, owing to the width oi stock:

As shown in Fig. 3, I prefer to construct the \boards (3 of two thin strips jor boards 11, the grain of which extends longitudinally of the boards, and secure them together with a layer or strip of leather belt-ing 12 or other suitable material between, by gluing. By placing the board under pressure while the glue is setting, the strips will be so firmly united to the leather that they can not be torn apart, and should the strips become split or otherwise broken in use, their parts will still be firmly held to the leather and thus pre- Vented from injuring the operator. The leather not only gives great tensile strength to the board, greatly lengthening its lile, but also increases its elasticity and (-onsrtpient frictional quality. 7

Material other than leather may be used, as illustrated in Fig. 4-, in which a strip of wire netting 13 is glued between the wooden strips, and it is evident that other materials may be used or a strip or layer of wood may be substituted for the leather in certain cases. Other means than gluing may be employed to unite the strips and I therefore do: not wish to'limit myself to the particular kind of material used or the particular In *ans employed for uniting the strips.

Having thus fully described my invention, what I claim is: I

, 1. A friction board for drorwiorging hammers consistingot outer strips oi wood Forming the friction surfaces of the board. and a strengthening strip of strong tlctibtc marom which motion is transmitted to the other by gears 5). Any suitable lllCcllillb. ism, as indicated at 10 may also-be provided to cause the rolls to frictionally engagethe board in raising the head and release theterial inlerposed between said outer strips Intestimony whereofl have signed this mid-eevured thereto throug'hout its length: specification in presence of two witnesses.

2. A friction board for Map-forging hum-- mers consisting of stripe of material frililil- 5 ing the friction surfaces Of the b0ard,'a1-id a Witnesses: v

sfrip of leather interposed between said lA-JWIS l). FLANimRs,

JO HN' A. BURGER.

' ;;sf.rips and secured thereto. i E, M, sm' 

